Vacation Archives - SIGMA Blog

What is a Zoom Lens and When to Choose a Zoom Lens?

Editor’s Note: This piece was originally published in 2014. In April 2020, it was revised to include updated product information and links, mirrorless zoom lens information etc.

What is a Zoom Lens?

A zoom lens is a type of camera lens that offers the photographer a useful range of different focal lengths in a single lens. This is in comparison to a prime lens, which only offers a single focal length. A zoom lens allows for quick and easy re-framing of a scene while staying in the same physical position. SIGMA offers a wide variety of zoom lenses, ranging from wide-angle zooms, super telephoto zoom lenses, and standard zoom lenses designed for everyday use.

Which SIGMA zoom lenses are right for you depends on your photographic intentions, budgets, and overall size constraints. In this article, we are going to explore many facets of zoom lenses for digital photography and explain the terminology, key features and benefits of the different types of zoom lens. We’re also going to showcase images made with a variety of SIGMA zoom lenses to illustrate key concepts.

Explore All SIGMA Zoom Lenses!

Zoom Ratio, and Constant-Aperture or Variable-Aperture Zoom Lenses

Zoom lenses always feature two focal lengths in the name which indicate the shortest and longest focal lengths in relation to the 35mm/full-frame sensor. To determine the overall zoom ratio of the lens, simply divide the longest focal length by the shortest. For example, the SIGMA 18-35mm F1.8 DC HSM | Art and the 8-16mm F3.5-4.5 are both examples of 2x zoom lenses: 35 divided by 16 equals 1.95, and 16 divided by 8 equals 2. (It is common practice to round to the nearest whole number or major fraction.)

Fall leaves seen through the SIGMA 18-35mm F1.8 DC HSM | Art lens at 24mm. 1/400 F4.5 ISO 100 on a Canon EOS Rebel T3i.

Same scene, seen through the same lens, this time fully zoomed to 35mm. Notice how the background is more abstract, even with the same F4.5 aperture as the previous shot at a wider field of view. A quick twist of the zoom ring can easily change the feel of the scene, and this is a key advantage of zoom lenses.

The 120-300mm F2.8 DG OS HSM | Sports is a 2.5x zoom lens and the 70-200mm F2.8 DG OS HSM | Sports is a 2.8 zoom lens. Zoom ratio only relates to the difference between the shortest and longest focal lengths, so the 150-600mm F5-6.3 Contemporary and Sports lenses are 4x zoom lenses, while the 60-600mm F4.5-6.3 DG OS HSM | Sports is a 10x high ratio zoom lens. All three of of these lenses offer the same maximum telephoto focal length, but the 60-600mm offers a much longer zoom range.

Here is a view of a rock quarry made with the vintage SIGMA 50-150mm F2.8 at 50mm on a Canon EOS Rebel T3i. Look at the shortest and longest focal length to determine the zoom ratio of a lens.

In this image, the camera is zoomed all the way to 150mm (and panned slightly right) and as you can see, that’s a 3x closer view. (150/50=3).

So, you can have a wide to short telephoto zoom lens with a higher overall zoom ratio than a telephoto to super telephoto zoom lens. For example, the 24-105mm F4 DG OS HSM | Art is a 4.3x zoom, while the huge 300-800mm F5.6 EX DG HSM lens is a 2.6x zoom lens, and the SIGMA 18-300mm F3.5-6.3 DC MACRO OS HSM | Contemporary is a wide to telephoto zoom lens with a very high zoom ratio. (We’ll let you do the math on this one!)

Zoom lenses also come in two main varieties: constant-aperture and variable-aperture. Each type has its strengths and purposes, depending on what is most critical to the photographer. When you look at the name of a zoom lens, if there is only a single aperture given, this is a constant aperture zoom lens. If there are two F-stops named with a dash in between, this is a variable aperture zoom lens.

The SIGMA 18-250mm F3.5-6.3 DC (OS)* MACRO HSM is a very high zoom ratio lens covering wide-angle to telephoto for APS-C DSLRs. Take a look at the view of the tip of Sandy Hook, NJ captured at 18mm on the Canon EOS Rebel T3i That’s a 28.8mm full-frame equivalent field of view.) This image was made wide-open at F3.5 at 1/1000 second.

Now, here the 18-250mm is zoomed all the way to 250mm (400mm full-frame equivalent). Divide the longest focal length by the shortest to determine the total zoom ratio of this lens. As you can see, this offers a much greater difference in the zoom ratio than the 3x zoom lens example shown earlier. This image was made wide-open, at F6.3 at 250mm, meaning that the shutter speed needed to slow down to 1/320 to expose the scene since the maximum aperture decreases as a variable-aperture zoom lens increases its focal distance.

Constant-Aperture zoom lenses keep the same maximum aperture throughout the entire focal range. So, for example, the 120-300mm F2.8 EX DG OS HSM | Sports and the 24-105mm F4 DG OS HSM | Art are both constant aperture zoom lenses. The key advantage of constant aperture zoom lenses is that you do not lose any light-gathering power as the focal length increases. This is helpful in challenging lighting situations, where the extra F-stops allow for faster shutter speeds. Autofocus operations inside a camera’s body also depend on the amount of light coming through the lens.

The SIGMA 17-50mm F2.8 EX DC (OS)* HSM is a constant-aperture zoom lens, meaning that at all focal lengths, the maximum aperture remains at F2.8. This is Sandy Hook lighthouse, captured in Infrared on the SIGMA SD1 at 17mm, the shortest focal length on this zoom lens.

For photographers who want to shoot wide-open in manual exposure mode, this also means you won’t be underexposing your shots as you zoom out, since the F-stop remains constant. Same goes for off-camera strobes—there doesn’t need to be any adjustments as you zoom to recompose with a constant aperture zoom lens.

This helicopter was captured with the SIGMA 120-300mm F2.8 DG OS HSM | Sports lens fully zoomed to 300mm. The aperture remains constant on this lens, which makes it great for long-reach photography with a fast shutter speed, since there’s no loss of light-gathering power as the lens zooms.

However, constant-aperture zoom lenses are limited in total zoom range: the 24-105mm F4 DG OS HSM | Art is the highest zoom ratio constant-aperture zoom lens in our catalog. And the demands of optical physics require a lot of big glass to make constant-aperture zooms, especially for the full-frame image circle.

Transit of Venus, captured with the SIGMA 50-500mm F4.5-6.3 10x zoom lens. The forecast called for clouds the whole day this last-in-a-lifetime event was taking place; but late in the afternoon, the clouds broke just enough to grab seven frames through the SIGMA SD1 at 500mm at F25. At 750mm equivalent on the Foveon APS-C sensor, this was a lot of reach in a lens I could quickly mobilize when the opportunity appeared. 1/8000 F25 ISO 100, worked up in SIGMA Photo Pro.

Variable-aperture zoom lenses feature two F-stops in the name, indicating the maximum aperture at the shortest and longest focal distance. This means that the overall light-gathering power of the lens decreases as the focal length increases, leading to slower shutter speeds at longer focal lengths. The benefits of this trade-off include more compact lens designs and higher zoom ratios.

Eastern Willets, seen through the 10x variable-aperture SIGMA 50-500mm zoom lens at 75mm on the SIGMA SD1. 1/640 F5.6 ISO 100.

A close-up shot of the Eastern Willet, from the same spot on the beach, by zooming this lens all the way to 500mm. Notice how these two images from the same spot, with the same lens, feel so different to one another. 1/640 F6.3 ISO 100 on the SD1.

One type of zoom lens is not “better” than the other in an absolute sense—each type of zoom lens has its appeal for different types of photographers and applications, depending on budget, weight considerations, and other variables.

Each SIGMA zoom lens is uniquely designed to create the best possible images throughout its zoom range. Here is the schematic of the new SIGMA 24-105mm F4 DG OS HSM | Art lens.

Whichever type of zoom lens it is, the SIGMA lens designers strive to create the best possible lens, incorporating aspherical, SLD and FLD elements as necessary to best transmit the scene to sensor. The optimum optical formula varies depending on the focal lengths, and the goal is to always design the best-performing lens possible within the design parameters.

What is “Optical Stabilizer”?

Many SIGMA zoom lenses feature an Optical Stabilizer, which is a floating lens group that counteracts slight camera movement during image capture—these lenses all have OS in the official lens name. The Optical Stabilizer acts like an invisible tripod, minimizing slight camera movements during longer exposures.

This image was captured at 3/10 second at 18mm on the SIGMA 18-250mm with Optical Stabilizer activated to keep the shot sharp by minimizing slight camera shake during the exposure. As you can see, it was long enough to blur the face of the person climbing down the stairs of the Sandy Hook lighthouse. Without OS, this shot would show serious camera-shake blur when hand-held at such a slow shutter speed.

This can help keep handheld shots sharp at slower shutter speeds. The general rule of thumb is that OS can help keep images acceptably sharp for a few stops under the reciprocal of the focal length, so, the effective slowest shutter speed for sharp shots will change as you zoom in or out. We take a long look at OS in this companion piece, if you want to learn more about how, when, and why to use OS when it is offered on a lens.

Why Use Tripod Collars?

Many of the larger SIGMA lenses ship with tripod collars. These tripod collars are paired with the lens because the tripod collar indicates where the center of gravity of the lens and camera resides. If you’ve got a lens that includes a tripod collar, you should always use this for mounting to a tripod, monopod, or other quarter-twenty threaded stabilizing accessory.

Don’t ever use the tripod socket in the base of your camera when paired with a lens that has a tripod collar. You can stress the lens and camera mounts, and while the center of gravity is under the tripod collar mounting point, this can lead to a tripod crashing over!

Versatility is the Key to the Appeal of the Zoom lens

Zoom lenses are designed to offer the photographer a great deal of flexibility in composition and framing without ever having to change lenses, or even physical position, for that matter. All it takes is a quick twist of the zoom ring and the composition can go from the shortest focal distance to the longest for a very different take of the scene presented before your lens. And many SIGMA zoom lenses offer true macro capture at the telephoto end, for close-up capture of tiny objects, adding to the overall versatility.

Early morning, Sandy Hook, NJ, captured at 17mm on the new SIGMA 17-70mm F2.8-4.0 DC MACRO (OS)* HSM | Contemporary. Here’s a wide-angle shot showing us exactly where these photos were made with the writing in the sand and the view north of the waters. The image is focused squarely on the sand-writing with some slight softening off the focal plane towards the horizon–typical of a wide-angle image that isn’t completely close-focused inches from the lens.

Now here is a detail of the “A” written in the sand, at closest focus at 70mm with this same lens. It is a very different image made just by zooming in and kneeling down to grab a close detail.

And keeping the lens at 70mm, but focusing a bit farther away and into the morning sun creates yet another very different image and takeaway from the same spot. Notice how the repetitive details get more abstract as your eye migrates upward through the frame. 1/1000 F4 ISO 200. All three of these images made with the SIGMA 17-70 lens on the Canon EOS Rebel T3i.

The depth of field in this image, made fully zoomed with the SIGMA 120-300mm F2.8 DG OS HSM | Sports lens, plus 1.4x teleconverter, on a the Canon EOS Rebel T3i with a 1.6x crop factor at closest focusing distance can be measured in grains of sand. 1/1000 F/4 ISO 100.

Of course, as you zoom in or out and recompose, the overall feel of the image can change dramatically, as a lens goes from a wide field of view to standard, or a standard field of view to super telephoto.

At 18mm with the SIGMA 18-250mm F3.5-6.3 on a Canon EOS Rebel T3i, the dune grasses seem to go on forever in this photo. Look at the horizon near the right edge of the frame and notice the red wing blackbird and the lighthouse. 1/1000 F6.3 ISO 100.

And now, we’ve zoom all the way in to 250mm, and focused right on the bird on the the evergreen branch. One lens, on scene, two very different photos taken moments apart thanks to the versatility of this high-ratio zoom lens!

Depth of field gets much more shallow as focal distance increases, even as telephoto compression diminishes the apparent relation between distant objects. The same scene can quickly be seen many different ways with a zoom lens. What’s most important is to choose the focal length and depth of field that will best capture what you are trying to say with your image.

Let’s take a look now at focal length and total reach of lenses, aiming at the Sandy Hook Lighthouse from the Observation Deck at North Beach a half mile North by Northeast of it. All images made on the Canon EOS Rebel T3i, with a 1.6x APS-C crop-sensor. Google Earth is a great tool for photographers!

Here is the view of the Sandy Hook Lighthouse from the North Beach Observation Deck, a half mile away, as seen through the SIGMA 8-16mm zoom lens at 16mm at F/13 for virtually limitless depth of field. The lighthouse is just a tiny mote inside that red highlighted box, which we’ll expand in the next photo.

If you look very closely at this detail of the 16mm framing, you can just make out a hint of the top of the lighthouse peeking out from between the branches.

Here we are seeing through the SIGMA 17-70mm F2.8-4.0 DC MACRO (OS)* HSM | Contemporary at 70mm. The distant lighthouse is still a very small background detail at this focal length and distance. At f/11 at this focal length and focal distance, we are hyperfocal, and both the branches and the lighthouse are sharp.

At 120mm on the SIGMA 120-300mm F2.8 DG OS HSM | Sports, the lighthouse is a bit bigger in frame, and even at F/11, the foreground foliage is defocused when we focus sharply on the distant lighthouse.

Here, we are zoomed in to 200mm on the 120-300mm. Notice both how the lighthouse is larger in frame, and how the foreground greenery is more blurred, again at F/11.

Here’s the same scene again through the 120-300mm, at 300mm this time. I opened the lens to F/4 as it was a bit windy, and the branches were swaying more, (as was the big lens on the tripod!) Notice how blurred the foreground branches are at this focal length and focal distance.

And finally, here is the lighthouse from a half-mile away at 420mm, again at F4 (the SIGMA 120-300mm F2.8 DG OS HSM | Sports plus a 1.4x teleconverter.) Focal length, aperture, and focal distance all play a role in object size in the frame and the presentation and apparent relationship of near and far details.

Zoom lens construction technology has come a very long way over the past forty years. And while it is still very typical for many zoom lenses to have some degree of field distortion at one end or the other of the zoom range as well as some slight vignetting at times, the overall image quality straight from the sensor of a modern zoom lens flat-out blows away the results of lenses from a few generations back.

The technical information for the SIGMA 17-70mm F2.8-4.0 DC MACRO (OS)* HSM | Contemporary lens shows the MTF chart, distortion and vignetting data at both 17mm and 70mm.

And when you add in the ease of use and accuracy of lens profile corrections that are bundled in most RAW conversion software programs such as the Adobe Camera Raw Engine that is the heart of Lightroom and Bridge/Photoshop toning, many of the historical disputes about prime lenses being the unsurpassed imaging kings don’t resound so absolutely any more.

Field distortion and any slight vignetting from a lens can quickly and easily be tuned during toning and processing in many image editing programs including the Adobe Camera Raw Engine in Lightroom and Photoshop/Bridge. In general, barrel and pincushion distortion effects are most noticeable in images that have crisp straight lines near the edges of the frame.

Crop-Sensor Cameras and Zoom Lenses

SIGMA offers many zoom lenses designed specifically for APS-C DSLRs. These lenses for the smaller image circle are designated with DC in the official name. And every DG lens for full-frame cameras will mount on the APS-C DSLRs in that same mount, too. All SIGMA lens focal lengths are given in relation to the full-frame size, whether it’s a DG or DC lens, so whenever a lens is mounted on an APS-C sensor camera, it is necessary to take the sensor size into account and adjust the apparent focal length and field of view accordingly. For most APS-C DSLRs, it is a 1.5x factor, so the SIGMA 10-20mm F3.5 EX DC HSM lens equates to a 15-30mm F3.5 zoom lens. (10 x 1.5 = 15) – (20 x 1.5 = 30).

This infrared scene was captured with the SIGMA SD1 and the 10-20mm F3.5 EX DC HSM lens at 10mm. Given the 1.5x APS-C sensor, this equates to 15mm on a full-frame camera. This zoom lens keeps the same maximum aperture throughout its zoom range. 1/80 F13 ISO 100, processed in SIGMA Photo Pro.

This is how it works, and this is how it is. On the shorter end of the focal lengths, it usually feels like APS-C is losing some of the wide-angle capabilities. But lenses like the pair of 10-20mm DC zooms and the 8-16mm F4.5-5.6 ultrawide zooms offer APS-C photographers incredibly wide fields of view that equate to the widest rectilinear fields of view for full-frame ultrawides.

This red winged blackbird fledging was captured with the SIGMA 50-500mm F4.5-6.3 zoom lens at 500mm on the SIGMA SD1. This DSLR has an APS-C sensor with a 1.5x factor, so it effectively offers more reach at the telephoto end: 750mm in this case, where 500mm x 1.5 = 750mm. The color, clarity, and overall presence of the images from the Foveon sensor is just amazing.

But this smaller sensor also means their is an apparent gain in focal length on the longer side of the zoom range. This means that a 200mm focal length on an APS-C DSLR is more like a 300mm field of view and a 500mm focal length is like 750mm on a full-frame camera. For wildlife photographers, this sensor factor can make distant animals bigger in the frame. And when it comes to full-frame lenses on APS-C DSLRs, the smaller image circle means that the image is captured with incredible sharpness from the center section of the lens.

Zoom Lenses and Macro

Many SIGMA zoom lenses offer a macro capture mode at the longest focal length at magnification ratios between one-third and one-half life sized reproduction. When a SIGMA zoom lens has “MACRO” in the official name, it means that it has a maximum magnification ratio of 1:3 or greater. This means that at the closest focusing distance, a one inch object will be rendered as one-third of an inch (.333 inches) on the sensor. (In the metric system, one centimeter equals 10 millimeters, so a one centimeter object is drawn across 3.3mms on the sensor.)

Macro focusing at the longest focal lengths allows from great up-close details and adds to the versatility of many SIGMA zoom lenses. Any SIGMA zoom lens that offers a maximum magnification of 1:3 or greater includes “MACRO” in the official lens designation. Search “MACRO” here on the SIGMA blog for tons of great advice on this specialized photo technique!

For many photographers first exploring macro capture, this a great way to get comfortable with the nuances of macro photography. At very close focusing distances, all motion is amplified. For example, a bit of jittery camera movement, and the slight swaying of a flower can mean the difference between having that ladybug perfectly in focus or having the subject drift out of the sharpness zone. Macro takes practice, and if you crave higher magnification than is offered at the far end of a the zoom, SIGMA offers a line of pro-caliber prime macros offer true 1:1 (life-sized) magnification for even more close-up details.

Check Out Our Selection of MACRO Lenses!

What SIGMA Zoom Lenses are Designed for Mirrorless and DSLR Cameras?

As of April 2020, SIGMA offers two mirrorless-exclusive zoom lenses, the 14-24mm F2.8 DG DN | Art and the 24-70mm F2.8 DG DN Art lenses. Additionally, many DSLR zoom lenses can be adapted to L-mount and Sony E-Mount cameras. Learn much more about which SIGMA lenses fit which camera systems here.

Which Zoom Lens is Right for Me?

Answering the question: “Which zoom lens is right for me?” depends on your photographic intentions. A single zoom lens such as the 18-250mm can cover wide-angle to telephoto, plus macro in a single lens, when traveling light with maximum versatility is the demand. Or a zoom lens like the 120-300mm F2.8 DG OS HSM can offer telephoto prime performance with the added benefit of a zoom range, along with the ultimate in lens customization when paired with the SIGMA-exclusive USB Dock and SIGMA Optimization Pro. The SIGMA 18-35mm F1.8 DC HSM is the world’s first F1.8 zoom lens for APS-C DSLRs and offers image quality that surpasses top-shelf prime lenses in independent lab testing. The pair of SIGMA 150-600mm F5-6.3 DG OS HSM zoom lenses offers incredible full-frame telephoto zoom range in two different designs, with optical stabilization. The SIGMA 17-50mm F2.8 EX DC (OS)* HSM and the 17-70 F2.8-4.0 DC MACRO (OS)* HSM | Contemporary are both fantastic standard zoom upgrades that blow away the standard kit lens that ships with so many DSLRs.

There’s a SIGMA zoom lens that’s right for just about every photographer on any budget. Check out the full lineup here!

Shop all SIGMA Zoom Lenses at sigmaphoto.com

Learn More on the SIGMA America Blog!

What is a Prime Lens?

Understanding Optical Stabilization

Shallow Depth of Field, Background Blur and Bokeh

Single-Shot Autofocus, or Continuous Autofocus, Or…

Making the Most of New Lenses, Cameras, and Other Photo Gadgetry

Sigma Gear for Summer Fun

Summer is a great time to hit the road and make amazing memories and fantastic photos! Wherever your trail leads, Sigma has a lens that is perfect for your vacation style!

To the beach, to the lakes, to the mountains! Sigma has a lens that’s perfect for your vacation style.

The best camera lenses for the beaches, bays, and lakes

All-in-one All-Star

This high zoom ratio lens covers a lot of focal distance without ever having to change lenses, perfect for sandy, mist-sprayed seasides. From wide angle to supertele with a flick of the wrist, it can take in the whole of the beach one instant, and then fill the frame with surfers on the waves, or birds on the rocks. Optical Stabilizer keeps shots sharp at slower shutter speeds, meaning you can skip the tripod in many situations. Adding to its versatility is its close-up abilities, offering 1:2 magnification with the close-up adapter lens, perfect for details of starfish, sandcrabs, and the most amazing shells. This is the best bargain one-lens solution around!

Travel with the 18-300mm | C lens!

Beaches, Boardwalks, and Fireworks: Day and Night specialist

The 17-70mm F2.8-4.0 DC OS Macro HSM | Contemporary is a serious upgrade to the standard kit lens. The fast-aperture design makes is perfect for seascapes, seaside portraiture, and boardwalk action shots both day and night, including fireworks. And 1:3 macro for closeups adds to the versatility.

See the 17-70mm F2.8-4.0 in action at the beach here!

Great Fireworks Tips and Tricks!

Best lenses for Birders on a budget

The Sigma 150-600mm F5-6.3 DG OS HSM | Contemporary lens is a full-frame supertelephoto zoom lens with Sigma’s incredible, exclusive feature set including lens customization for AF speed, focus limiters, and zoom lock at all marked focal lengths. This lens delivers outstanding long-reach imagery of shorebirds, windsurfers, sailboats and other seaside subjects. Want even more reach? Bundle it with the 1.4 teleconverter!

Terns on the beach, as seen through the 150-600mm Contemporary lens. 1/1250 F8 ISO 400 at 600mm on a 6D.

Learn why this lightweight supertele is a game-changer for all-day long-reach photography!

Another great lightweight option is the 100-400mm F5-6.3 DG OS HSM | Contemporary lens! At just over two and a half pounds, this bantam zoom offer long reach, blazingly fast autofocus and Sigma’s exclusive lens customization with the USB Dock.

A snowy egret takes flight from a tidal pond as seen through the Sigma 100-400mm F5-6.3 DG OS HSM | Contemporary lens paired with a Canon 6D. 1/1000 F6.3 ISO 500 at 400mm.

See the 100-400mm in a birding sneak peek posting!

The Best Compact Supertelephoto Zoom lens for Photo Safaris

The Sigma 60-600mm F4.5-6.3 DG OS HSM | Sports lens is the world’s only 10X high-zoom ratio standard to supertelephoto zoom lens with a long end of 600mm. As an added bonus, it captures 1:3 magnification macro close-ups at 200mm. And the Multi-material design keeps it a lightweight six and a half pounds. Weather-sealed and ready for adventure? You know it! Pair it with an Art line wide angle and you’ve got wide to far and close up covered!

Continue reading Sigma Gear for Summer Fun

The Sigma 18-300mm F3.5-6.3 | C lens is Always Ready For Anything!

The Sigma 18-300mm F3.5-6.3 DC OS HSM Macro | Contemporary lens is best described as versatile . At just four inches long in the camera bag, and weighing just over a pound, this small lens covers wide angle to supertele, plus macro. It’s the photographic equivalent of a chameleon, the pocket multi-tool, or a superhero’s quick-changing boat/car/plane combo-vehicle. As an athlete, it would compete in the decathlon, ready to adeptly pivot from one specialty to the next.

Our team of bloggers has taken this lens everywhere from open-air biplanes, to skiing in the Alps, to bear-spotting in Alaska, backpacking the Pacific Northwest, and on family vacations to showcase the wide compositional range and total image quality this superzoom superstar delivers day in and day out in pretty much any situation you can imagine! Here’s a sampling of situations where the Sigma team has taken this amazing all-in-one lens. Where would you take it next?

Click each red headline link to read the full report!

Brown Bear Cubs in Alaska

Traveling on a small planes with serious weight restrictions, Sigma Pro Robert O’Toole packed the 18-300mm lens for maximum versatility in a compact package and made some amazing shots of the beautiful bears.

© Robert O’Toole
Cub image.
Sigma 18-300 C and Nikon D500, 48mm, 1/500s at f/16, handheld, manual mode.

“The 18-300mm F3.5-6.3 DC OS Contemporary lens is so small and lightweight that it makes it a great choice when you need to count pounds.” ~ Robert

Continue reading The Sigma 18-300mm F3.5-6.3 | C lens is Always Ready For Anything!

Sigma’s Summer Gift Guide: Great Gear for Dads, Grads, and Everyone

Whether as a gift for your favorite dad, or recent grad, or for yourself before a big summer adventure, there’s great Sigma gear for everyone’s photographic style!

The best camera lenses for the beach

17-70mm F2.8-4.0 DC OS HSM | Contemporary

Covering wide to short telephoto, this zoom lens is perfect for switching for wide scenes to closer portraits, at the height of day. And with a faster maximum aperture at all focal lengths than the typical kit lens; it’s also perfect for twilight portraiture and nightscapes. Offered at $399 through June 30th on Instant Savings!

18-300mm F3.5-6.3 DC OS HSM | Contemporary

The Sigma 18-250mm F3.5-6.3 Macro is Ready for Adventures

by Jack Howard

When traveling as light as possible while maximizing versatility, an all-in-one zoom lens like the new Sigma 18-250mm F3.5-6.3 Macro is a great choice. This recently redesigned lens is built specifically for DSLRs with the smaller APS-C sensors, and now adds 1:2.9 macro capture for even more flexibility and creativity in an even more compact package than its predecessor (which we explored in detail last summer.) From wide angle to supertelephoto and macro for close-up details, this one lens is ready for just about any adventure.

To bullet it out, here’s why this optically stabilized superzoom is a great choice for many photographers.

This lens is an impressive combination of reach, range and versatility in a single multi-tasking piece of glass that can do just about everything from wide landscapes, to telephoto wildlife, macros (1:2.9 max magnification), short tele portraiture, and help make a strong shot of most situations you’ll want to shoot on your adventures, without ever having to swap lenses.
This APS-C specific lens is a 13.8x optically stabilized zoomer that weighs in at just a pound plus an ounce with a field of view range comparable to about a 28-400mm on a full-frame camera. That’s a whole lot of lens in a compact 3.5 inch long package!
When travelling with young children and all the gear kids require, there’s just not room for a big, dedicated camera bag any more.
Maximum versatility in tight quarters. Helicopter tours, and lighthouse climbs are but two examples of tourist activities that can be amazingly “cozy” situations where it isn’t necessarily possible or practical to try to switch lenses to make different shots.

Walking along the High Line Park in Manhattan, the new Sigma 18-250mm F3.5-6.3 DC OS HSM Macro offered a ton of compositional versatility from wide angle, normal perspective, and telephoto. Here's a detail of the skyline from the Highline shot at 61mm on a Canon EOS Rebel T3i. 1/160 F11 ISO 100. (All shots in this article made with the Rebel T3i.)

But this multitasker makes some smart tradeoffs to be very adept in many types of photography in its small, economical package. And when you bump the street price of the 18-250mm up against some of the more specialized lenses, you start to realize that it’s a very capable tool that can be put on your SLR and be ready to capture great photos of pretty much anything you can see through that viewfinder, from sweeping vistas to to distant sports and wildlife action in one easy-to-handle lens.

Continue reading The Sigma 18-250mm F3.5-6.3 Macro is Ready for Adventures

Sigma 18-250mm F3.5-6.3 DC Macro OS HSM: First Impressions with Walter Arnold

Pro Photographer Walter Arnold has been shooting new ad campaign shots with the new Sigma 18-250mm F3.5-6.3 DC Macro OS HSM on the sly for the past few weeks. We spent a few minutes talking with him about his experiences with this amazing new superzoom. For full press release and technical specifications click here.

For this shot I borrowed some brushes from local Water Color artist Sterling Edwards, who also works in acrylics. He lent me some of his brushes as well as a painter's pallet to photograph for this shoot. I laid a few of the brushes on the pallet next to a colorful dollop of ink. After spending a good deal of time lighting the brushes with traditional lighting techniques, I broke out my trusty mag lite flashlight and used it to provide a very focused light from the side which made for a dramatic and textured image. F22 0.4s ISO100 250mm Manual. ©2012 Walter Arnold.

Continue reading Sigma 18-250mm F3.5-6.3 DC Macro OS HSM: First Impressions with Walter Arnold

Understanding Optical Stabilization

Many lenses in the SIGMA line feature Optical Stabilization, which is a great feature for helping photographers nail sharp shots when camera shake may be an issue.

SIGMA lenses with “OS” in the name include this technology which employs motion sensors to control floating lens groups to counteract camera movements which can cause undesirable blur from hand-holding shots with slower shutter speeds. Putting it another way: Optical Stabilization works as a sort of invisible tripod to hold the camera steady for shutter speeds longer than the reciprocal of the focal length.

Optical Stabilization is a great lens feature for controlling one type of undesirable and unintentional source of blurring in photographs–slight camera motions during capture when the shutter speed is longer than the reciprocal of the focal length (longer than 1/100 for a 100mm focal length, longer than 1/50 for a 50mm focal length, longer than 1/500 for a 500mm focal length, as a few examples.)

Long ago this rule of thumb was simply this simple:

“When you’ve got a shutter speed longer than one over the focal length, use a tripod.”

But since Optical Stabilization came along, it’s now a bit longer:

“When you’ve got a shutter speed longer than one over the focal length, you might use a tripod, or you can switch on Optical Stabilization and gain a few stops ‘wiggle room’ for handholding.”

How much slower than the focal length you can go varies slightly from person to person, based on overall levels of jittery-ness. (A trained sharpshooter will most probably have much better luck straight out of the gate than a DSLR beginner on too much coffee!), but most photographers should easily see much sharper images with OS activated at shutter speeds a few stops below the focal length reciprocal with just a little practice and understanding of what OS is, and what it does and how it does it–(as well as what it’s not, and what it can’t do.)

Understanding Blur

Before we go any further, we need to talk a bit about blur. (Please try to focus on this section!)

There are many types of blur associated with photography. Some are absolutely desirable, and some, not so much. For example, shallow depth of field that creates fore- and background blur, making the subject pop, is often pleasing and desirable. But having the subject out of focus (or having nothing in the frame whatsoever in focus) isn’t as pleasing.

Motion blur to express or indicate speed or movement can sometimes be a successful technique. This can be accomplished with either camera or subject movement, or both.

Then there’s plain old camera shake. These slight, unintended camera movements when the shutter speed is slower than the reciprocal of the focal length belongs almost unequivocally in the undesirable category. It doesn’t matter where you are focused in the frame–if the camera jerks too much during capture (per the focal length-reciprocal rule) all the stationary points in the field of view are recorded as motion traces. And this–and only this–is what Optical Stabilization corrects.

Both of these shots of Buttermilk Falls at Washington Valley Park in Bridgewater, NJ were made hand-held at 1/10 second, ISO 100, F18 with a Circular polarizer and 1-stop Neutral Density in front of the lens. At left, we have Optical Stabilization active on the SIGMA 18-250mm superzoom lens mounted on a Canon EOS Rebel XTi, and and right, it is turned off. As you can see, with OS activated, our rocks and still objects in the frame are sharp and crisp, and at right without OS, everything in the image is a bit of a blur.

When activated, the Optical Stabilization technology inside a SIGMA lens senses slight motion of the camera and lens combination in the photographer’s grip and sends signals to the OS system’s floating lens group to cancel out the movement with an opposite reaction. So, the light rays reaching the sensor plane from stationary objects in the frame will still be recorded to the sensor at only one location–instead of with that undesirable jittery camera shake effect.

Got it? Optical Stabilization technology only detects and corrects for slight camera and lens movements during capture. It does not and can not control what is happening outside of the camera.

Think about it like this for a second: your shock absorbers can smooth out the bumps your car encounters, but it cannot do a thing to smooth out the ride for passengers in the car ahead of or behind you. Likewise, OS can’t freeze moving subjects in your frame. (There’s a whole different sets of rules of thumb for that–object motion is amplified by direction, speed and focal length.)

Make sense so far? Optical Stabilization behaves like an invisible tripod: it holds the camera steady, and helps you keep sharp, crisp edges of stationary subjects.

So let’s follow this path a little while longer: OS allows you to use slower shutter speeds–without a tripod–to capture images where discrete, still points in the frame will be drawn to the sensor as discrete still points instead of tracers following the path of camera movement during the longish exposure. And choosing a slower shutter speed can allow for a smaller aperture for more depth of field, or to keep a camera from having to climb up to a higher (noisier) ISO setting. But a slower shutter speed can also emphasize movement in the frame, as moving objects in the frame will be recorded across a trajectory of pixels during the exposure with either OS or a tripod.

To illustrate this story I visited a waterfall for some sample shots where we want long exposures to emphasize the flowing water, but want our rocks and foliage in the frame to be nice and sharp. To make this more exciting, I also drank a bit too much coffee before beginning my hike to really push the OS function in my 18-250mm lens! As it was midday, I had to fit my lens with a polarizer and a neutral density filter to get long enough shutter speeds to make the cascading water blur nicely, even when stopped way, way, way down to F16 and F18!

Here’s a bigger version of the OS-active waterfall shot we showed above. As you can see, the water has very nice flowing motion, and the stationary edges in the frame are perfectly sharp. This was made handheld at 1/10 second, ISO 100, F18 at 28mm. Yes, the top spill is a bit askew from frame edge, but that’s easy enough to fix in any basic image editor. We’re about a stop-and-a-half below the 1/x focal length rule here. Note that with zoom lenses, the 1/x rule for OS and shutter speed relates to the current focal length!

Now here we are zoomed in at 95mm with this same lens, again with OS activated. This was shot at 1/15s, F16, ISO 100. Without OS, there’s no way this hand-held shot would be sharp at this aperture and shutter combination that just about 3 stops below the 1/x rule!

And here, we’re zoomed in even tighter, to 150mm. Our shutter speed here is 1/50 second at F13, again with Optical Stabilization active, and again, with a shutter speed well below the reciprocal of the focal length. OS holds the camera steady, so the rocks and fallen log is nice and crisp, but the water still flows nicely in the frame during this telephoto exposure.

I framed this self portrait in the reflection of the neutral density filter in front of my SIGMA 18-250mm lens. I set the Rebel XTi’s pop-up flash to -⅔ for some subject fill. 1/13, F13, ISO 100 with OS activated. It’s just a little under the 1/x rule at widest focal length on this lens, but it sure helped here, as I’d had too much coffee, and was balancing on some uneven rocks, with the camera held at arm’s length to make this on-location self portrait.

It makes sense, right? Optical Stabilization negates the effects of slight camera movement during capture, but it cannot control motion happening outside the camera.

But do also note: In order to give the appearance of stillness/sharpness to an object moving parallel to the capture sensor, the camera and lens must move at a pace that matches the speed of the object moving through the frame. This is called “panning”, and some of our larger OS lenses offer not only ON and OFF for OS, but OFF/ 1 & 2. On SIGMA lenses with Off/1/2 controls, OS 1 corrects for any lens movements, while OS 2 only corrects for vertical shakes–meaning you can follow and pan fast-moving objects with or without a tripod, and the OS won’t correct for the chasing of the subject along the horizontal axis.

Making Optical Stabilization Work for You

Understanding how OS works, and knowing when and why to activate this cool feature on many SIGMA lenses goes a long way towards making it work for you. For example, if you are shooting at shutter speeds that are above the reciprocal of the focal length, there’s not really a reason to have OS on–for example, bright daylight sports action with an F2.8 lens with shutter speeds above 1/1000 second when the creative decisions call for very fast action-freezing exposures.

But when it’s not possible or practical to employ a monopod or tripod to get sharp shots with slow shutter speeds, being able to simply flip the OS switch on SIGMA lenses to make a sharp frame in dim conditions–or to get more Depth of field in your macros and telephoto detail shots–is a great thing!

I made this shot inside a lighthouse at 3/10 second to illustrate the versatility of the SIGMA 18-250mm superzoom, and without OS, it just wouldn’t work at all.

And here’s a pair of shots I made while I was working on a piece about the SIGMA 120-300mm F2.8 at 300mm. The top image is shot wide open at F2.8 @ 1/4000. This is much faster then the reciprocal of the focal length, so it is sharp on the focal plane, but the flowers even a few inches behind are soft. Stopping down to F16 gives us much more depth of field, but to keep it properly exposed, our shutter speed is 1/125–below the reciprocal of the 300mm focal length. Activating Optical Stabilization allows us to make this shot and keep it sharp and free of camera shake without having to haul a tripod along!

When possible, try to make a quick burst of shots of the scene, as the frames in the middle of a burst usually have a bit more stillness about them (squeezing the shutter introduces additional camera shake), and again, if possible, frame the shot through the optical viewfinder (as opposed to live view LCD mode) to also up the odds of nailing sharp shots when really pushing the stops below the 1/x rule.

When activated and used wisely, Optical Stabilization can very often mean the difference between making a winning frame and making a blurry mess. It does takes a bit of practice and understanding to make the most of it, but it really can help make keeper frames in challenging conditions.

Do you have any shots and stories to share of when and where Optical Stabilization helped you make a sharp shot? Share a link below or post it to our Facebook wall!

Traveling light with the Sigma 18-250mm F3.5-6.3 DC OS HSM

There are times when packing light really is what matters most for photo adventures. And on those occasions when hauling a big camera bag with a bunch of specialty lenses isn’t an option for one reason or another, a multi-purpose superzoom lens such as the Sigma 18-250mm F3.5-6.3 DC OS HSM is a great choice.

This lens is an impressive combination of reach, range and versatility in a single multi-tasking piece of glass that can do just about everything from wide landscapes, to telephoto wildlife, close-ups (1:3.4 max magnification), short tele portraiture, and help make a strong shot of most situations you’ll want to shoot on your adventures, without ever having to swap lenses. And it does all this at a very attractive street price, I might add!

Watch this short video for a hands-on demonstration of the features and functions of this lens.

The Sigma 18-250mm F3.5-6.3 DC OS HSM is available in Sigma, Canon, Nikon, Pentax and Sony/Minolta mounts for APS-C cameras.

This APS-C specific lens is a 13.8x optically stabilized zoomer that weighs in at just over a pound and a half with a field of view range comparable to about a 28-400mm on a full-frame camera. That’s a whole lot of lens in a compact four-inch long package! You can check out the full product specs, including SLD and Aspherical lens element construction that help keep shots sharp and crisp through the full focal range here.

Continue reading Traveling light with the Sigma 18-250mm F3.5-6.3 DC OS HSM